Design And Implementation Of White Space Query Mechanism

With the increasingly widespread use of wireless communication applications, spectrum resources become more and more scarce.And with the development of varies of wireless network technologies such as wireless WAN, wireless LAN, and wireless personal area network, limited spectrum resources have gradually can not meet the needs of growing data transmission in mobile applications. However, with contradictions, national spectrum resources management department assigned specific licensed bands to some specific communication services (such as television broadcasting services, etc.), but these licensed bands may not be occupied in a certain place and time.The utilization rate of spectrum resources is very low.In order to solve the problem of the lack of spectrum resources, we urgently need to improve the utilization of the available spectrum。 That is, using white space in all kinds of communication services as much as possible. White space are portions of the radio spectrum that are allocated to a licensed, primary user but are unused or unoccupied at specific locations and times.In order to make the wireless devices get available bands in a specific time and specific location, people need to develop a mechanism to discover and get the white space, so that wireless devices can make use of unused spectrum and improve its utilization.Firstly, this paper introduces relative definitions and recent researches about white space.It lists white space related research institutions such as the PAWS working group of IETF, FCC, ECC, Ofcom, and describes their research achivements. Secondly, this paper analyzes the requirements of the protocol to access white space database in both functionality and performance. It describes the services the protocol must provide as well as other non-functional requirements such as applicability, security and so on.Thirdly, on the basis of the references of above research institutions as well as the reqirements analysis, this paper makes design and implementation of the protocal to access white space database. It includes the design of protocol architecture, protocol status, protocol process, protocol message format, and the white space database schema. In order to verify the the protocol to access white space database designed, this paper designs and implements a white space query system in ns3simulation environment, thus the white space query protocol can be deployed in LTE mobile communication network simulation scenario.Finally, the paper summarizes the inadequacies in the work and further possible research directions, and lists the work I completed during my graduate study.